<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 ---------------

                                   FORM 10-K/A

       FOR ANNUAL AND TRANSITION REPORTS PURSUANT TO SECTIONS 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

(MARK ONE)
[X]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934

     For the fiscal year ended December 31, 1998

                                       OR

[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934

     For the transition period from _____________ to _______________

                         Commission File Number: 1-9511

                       THE COAST DISTRIBUTION SYSTEM, INC.
             (Exact name of Registrant as specified in its charter)

        Delaware                                         94-2490990
(State of Incorporation)                              (I.R.S. Employer
                                                     Identification No.)

               350 Woodview Avenue, Morgan Hill, California 95037
          (Address of principal executive offices, including zip code)

       Registrant's telephone number, including area code: (408) 782-6686

Securities registered pursuant to Section 12(b) of the Act:

                                                        Name of each exchange 
        Title of each class                              on which registered
        -------------------                              -------------------
Common Stock, par value $.001 per share                American Stock Exchange

Securities to be registered pursuant to Section 12(g) of the Act: None

Indicate by check mark whether the registrant: (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes [X]  No [ ]

Indicate by a check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [X]

The aggregate market value of the voting stock held by non-affiliates of the
Registrant, as of March 17, 1999, was approximately $10,229,000 (based upon the
closing price for shares of the Registrant's Common Stock as reported by the
Nasdaq National Market for the last trading date prior to that date). Shares of
Common Stock held by each officer, director and holder of 5% or more of the
outstanding Common Stock have been excluded in that such persons may be deemed
to be affiliates. This determination of affiliate status is not necessarily a
conclusive determination for other purposes.

On March 17, 1999, approximately 4,829,640 shares of the Registrant's Common
Stock, par value $.001 per share, were outstanding.

                      DOCUMENTS INCORPORATED BY REFERENCE.

                                      NONE

<PAGE>   2

                                    PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

<TABLE>
<CAPTION>

        Name                           Age           Position
        ----                           ---           --------
<S>                                    <C>   <C>
Thomas R. McGuire..................    55    Chairman of the Board,
                                             Chief Executive Officer and Director

Sandra A. Knell....................    41    Executive Vice President - Finance,
                                             Chief Financial Officer and Secretary

Jeffrey R. Wannamaker..............    38    Executive Vice President and President of the
                                             Distribution Division of the Company

David A. Berger....................    45    Executive Vice President

Dennis A. Castagnola...............    51    Executive Vice President and President of
                                             the DTS Products Division of the Company

Louis B. Sullivan..................    74    Director

John E. Turco......................    68    Director

Ben A. Frydman.....................    52    Director

Robert S. Throop...................    61    Director

John W. Casey......................    55    Director
</TABLE>

        Thomas R. McGuire is a founder of the Company and for more than five
years has been Chairman of the Board and Chief Executive Officer of the Company.
From 1981 until August 1985 he also served as the Company's Chief Financial
Officer and Secretary.

        Sandra A. Knell has been the Company's Executive Vice President -
Finance, Chief Financial Officer and Secretary since August 1985. From 1984
until she joined the Company, Mrs. Knell was an Audit Manager, and for the prior
four years was a senior and staff accountant, with Grant Thornton (formerly
Alexander Grant & Co.). Mrs. Knell is a Certified Public Accountant.

        Jeffrey R. Wannamaker, who joined the Company in 1984, has been
Executive Vice President - Operations since 1995. From 1991 and until his
promotion to Executive Vice President, Mr. Wannamaker held the position of
Senior Vice President - Branch Operations of the Company. Prior to that time he
held various other management positions with the Company. In 1997, Mr.
Wannamaker was appointed as President of the Company's Coast Distribution
Division which markets and supplies products to RV and boating After-Market
Customers.

        David A. Berger served as Executive Vice President - Marketing from May
1988 until September 1993. Due to the growth of the Company's marine products
sales, in September 1993 the Company's marketing department was restructured
into two separate departments, one for marine products and the other for R.V.
products, and Mr. Berger was placed in charge of marketing for the Company's
marine products division. From August 1986 to May 1988, Mr. Berger was Senior
Vice President - Purchasing of the Company. For the prior 14 years he held
various management positions with C/P Products Corp., a distributor of
recreation vehicle parts and accessories acquired by the Company in 1985.


                                      -2-
<PAGE>   3

        Dennis A. Castagnola was appointed to his current position of Senior
Vice President-Proprietary Products in May 1994, in which he directs the
Company's Proprietary Products program. From September 1993 until May 1994, he
served as Senior Vice President - R.V. Sales and Marketing. For the prior 19
years, he held various positions with the Company, including Vice
President/Division Manager of the Company's Portland, Oregon Distribution
Center. In 1997, Mr. Castagnola was appointed as President of the Company's new
DTS Division which markets and supplies proprietary products to RV and boating
manufacturers and to customers in markets other than the RV and boating
After-Market.

        Louis B. Sullivan has served as a director since 1977, and has been a
rancher and private investor since March 1984.

        John E. Turco has served as a director since 1977, and has been a
private investor since 1988, investing primarily in agricultural businesses.

        Ben A. Frydman has served as a director sine 1988. Mr. Frydman is, and
for more than five years has been, engaged in the private practice of law, as a
member and shareholder of Stradling Yocca Carlson & Rauth, a Professional
corporation, which provided legal services to the Company in 1997.

        Robert S. Throop has served as a director since 1995. Until his
retirement in late 1996, and for more than five years prior thereto, Mr. Throop
was the Chairman and Chief Executive Officer of Anthem Electronics, Inc.
("Anthem"), which is a national distributor of semiconductor and computer
products. Mr. Throop is also a director of Arrow Electronics, Inc., the
corporate parent of Anthem, and the Manitowoc Company.

        John W. Casey has served as a director since August 1998. From 1980 and
until his retirement in 1994, Mr. Casey was President and Chief Executive
Officer of Shurflo Pump Mfg. Company ("Shurflo"), which is engaged in the
manufacture and sale of pumps used in pumping and circulating water or other
liquids in a variety of products and equipment, including recreational vehicles
and soft drink dispensing machines. Mr. Casey serves as a director of Shurflo,
the Deschutes Basin Land Trust and the RV/MHI Heritage Foundation, Inc.


                                      -3-

<PAGE>   4

ITEM 11. EXECUTIVE COMPENSATION

        The following table sets forth compensation received for the three
fiscal years ended December 31, 1998, by the Company's Chief Executive Officer,
and the other executive officers whose aggregate cash compensation for services
rendered to the Company in all capacities in 1998 exceeded $100,000
(collectively, the "Named Officers"):

                           SUMMARY COMPENSATION TABLE

<TABLE>
<CAPTION>
                                                                                LONG-TERM
                                                                               COMPENSATION
                                                                               ------------
                                                                                  AWARDS
                                                                               ------------
                                           ANNUAL COMPENSATION                  SECURITIES
   NAME AND PRINCIPAL           ------------------------------------------      UNDERLYING
        POSITION                YEAR           SALARY($)          BONUS(1)      OPTIONS(#)
-------------------------       ----           ---------          --------     ------------
<S>                             <C>            <C>                <C>          <C>
Thomas R. McGuire               1998           $248,276           $20,000            -0-
  Chairman of the Board         1997            248,303               -0-         47,500
  and Chief Executive Officer   1996            263,532            59,250            -0-

Sandra A. Knell                 1998            143,366            13,500         50,000
  Chief Financial Officer       1997            134,039               -0-         20,000
  and Executive Vice            1996            121,192            30,500            -0-
  President

Jeffrey R. Wannamaker           1998            160,193            16,500         50,000
  Executive Vice President      1997            134,039               -0-         20,000
  and President of              1996            121,192            30,500            -0-
  Distribution Division

David A. Berger                 1998            112,116            10,000         20,000
  Executive Vice President      1997            106,542               -0-         20,000
                                1996            102,248            30,500            -0-

Dennis A. Castagnola            1998            112,116            10,000         20,000
  Executive Vice President      1997            108,437               -0-         12,500
  and President of the          1996             94,313            22,100            -0-
  DTS Division
</TABLE>

-----------------
(1) Bonuses were awarded under annual incentive compensation plans.


                                      -4-

<PAGE>   5

OPTION GRANTS

<TABLE>
<CAPTION>
                                                                               POTENTIAL REALIZABLE VALUE
                                      PERCENT OF                                  OF OPTIONS AT ASSUMED  
                       NUMBER OF     TOTAL OPTIONS                                ANNUAL RATES OF STOCK  
                       SECURITIES     GRANTED TO                                 PRICE APPRECIATION FOR  
                       UNDERLYING    ALL EMPLOYEES    EXERCISE                      OPTION TERM(4)       
                        OPTIONS        IN FISCAL       PRICE       EXPIRATION  ------------------------- 
       NAME            GRANTED(1)       YEAR(2)     ($/SHARE)(3)      DATE         5%            10%     
       ----            ----------    -------------  ------------   ----------  ----------    ----------- 
<S>                    <C>           <C>            <C>            <C>         <C>           <C>
Thomas R. McGuire           -0-           0.0%         N/A             N/A     $    -0-       $    -0-
Sandra A. Knell          50,000          28.9         3.1875         1/07/08    100,000        254,000
Jeffrey R. Wannamaker    50,000          28.9         3.1875         1/07/08    100,000        254,000
David A. Berger          20,000          11.6         3.1875         1/07/08     40,000        101,600
Dennis A. Castagnola     20,000          11.6         3.1875         1/07/08     40,000        101,600
</TABLE>

----------------------
(1)     These options vest in five equal annual installments of 20% of the
        shares covered by such options. Each option is subject to termination in
        the event of the optionee's cessation of employment with the Company.

(2)     Options to purchase an aggregate of 173,000 shares were granted to all
        employees in fiscal 1998, including the Named Officers. Each
        non-employee director received options to purchase 2,000 shares in 1998.

(3)     The exercise price may be paid in cash, in shares of the Company's
        Common Stock valued at fair market value on the date of exercise, or
        through a cashless exercise procedure.

(4)     There is no assurance that the values that may be realized on exercise
        of such options will be at or near the values estimated in the table,
        which arbitrary compounded rates of growth of the price of the Company's
        stock of 5% and 10% per year.

OPTION EXERCISES AND FISCAL YEAR-END VALUES

        There were no option exercises by any of the Named Officers in 1998. In
addition, none of the Named Officers held any in-the-money options as of
December 31, 1998.


                                      -5-

<PAGE>   6

                        COMPENSATION COMMITTEE INTERLOCKS

        In fiscal 1998, the members of the Compensation Committee were Louis B.
Sullivan, Robert S. Throop, and John E. Turco, each of whom is a non-employee
director of the Company.

                             DIRECTOR'S COMPENSATION

        Directors who also are Company employees receive no compensation for
serving as directors. Non-employee directors are paid a retainer of $6,000 per
year and receive $1,500 for each Board of Directors' meeting attended and are
reimbursed for the out-of-pocket expenses incurred in attending those meetings.
No compensation is paid for attending meetings of Committees of the Board of
Directors on which directors serve. Pursuant to the Company's 1993 Employee
Stock Option Plan, each year each non-employee director is automatically granted
an option to purchase 2,000 shares of Company stock at an exercise price that is
equal to the fair market value of the shares on the date of grant. These options
become fully exercisable six months after the date of grant. Upon joining the
Board, each new non-employee director receives an option to purchase 2,000
shares, which becomes exercisable in full one year after the date of grant.

      COMPLIANCE WITH SECTION 16(a) OF THE SECURITIES EXCHANGE ACT OF 1934

        Based on its review of copies of reporting forms and certifications of
the Company's directors and executive officers, the Company believes that all
filing requirements under Section 16(a) of the Securities Exchange Act of 1934
applicable to its directors and executive officers in the year ended December
31, 1998 were satisfied.


                                      -6-

<PAGE>   7

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

        The following table sets forth, as of March 17, 1999, information
regarding the ownership of the Company's outstanding common stock by each person
known to management to own, beneficially or of record, more than five percent
(5%) of the common stock and by each director and the Named Officers of the
Company and all directors and officers of the Company as a group.

<TABLE>
<CAPTION>
                                                 AMOUNT AND
      NAME AND ADDRESS                            NATURE OF                         PERCENT
     OF BENEFICIAL OWNER                    BENEFICIAL OWNERSHIP(1)                 OF CLASS
     -------------------                    -----------------------                 --------
<S>                                         <C>                                     <C>
     Thomas R. McGuire                            657,829(2)                         13.9%
        1982 Zanker Road
        San Jose,  CA 95112
     Dimensional Fund Advisors Inc.               404,600(3)                          8.3%
        1299 Ocean Avenue
        Santa Monica, CA  90401
     John E. Turco                                222,192(4)                          4.6%
     Louis B. Sullivan                            130,470(4)                          2.7%
     John W. Casey                                  9,000(4)                           *
     Ben A. Frydman                                13,000(4)                           *
     Robert S. Throop                              15,000(4)                           *
     Sandra A. Knell                               92,465(5)                          1.9%
     Jeffrey R. Wannamaker                         72,490(5)                          1.5%
     David A. Berger                               60,831(5)                          1.2%
     Dennis A. Castagnola                          21,246(5)                           *
     All directors and officers
       as a group (10 persons)                  1,315,523(6)                         25.7%
</TABLE>

------------------
 *    Less than 1%.

(1)   Except as otherwise noted below, the persons named in the table have sole
      voting and investment power with respect to all shares shown as
      beneficially owned by them, subject to community property laws where
      applicable.

(2)   Does not include an aggregate of 50,016 shares held in trust for the
      benefit of Mr. McGuire's adult children, as to which Mr. McGuire disclaims
      beneficial ownership. Includes 34,750 shares subject to outstanding stock
      options exercisable during the 60-day period ending May 17, 1999.

(3)   In a report filed with the Securities and Exchange Commission, Dimensional
      Fund Advisors, Inc., a registered investment advisor ("DFA"), has reported
      that all 404,600 shares are held in portfolios of DFA Investment
      Dimensions Group, Inc., a registered open ended investment company or in
      series of the DFA Investment Trust Company, a Delaware business trust , or
      the DFA Group Trust and DFA Participation Group Trust, investment vehicles
      for qualified employee benefit plans for which DFA serves as investment
      manager. DFA disclaims beneficial ownership of all such shares.

(4)   Includes shares subject to outstanding stock options, as follows: Mr.
      Sullivan -- 12,000 shares; Mr. Turco -- 12,000 shares; Mr. Frydman --
      12,000 shares; and Mr. Throop -- 10,000 shares.

(5)   Includes shares subject to outstanding stock options exercisable during
      the 60-day period ending May 17, 1999, as follows: Ms. Knell -- 54,500
      shares; Mr. Wannamaker -- 54,500 shares; Mr. Berger -- 42,500 shares; and
      Mr. Castagnola -- 16,750 shares.

(6)   Includes 251,000 shares subject to outstanding stock options exercisable
      during the 60-day period ending May 17, 1999.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

      None. 


                                      -7-

<PAGE>   8

                                   SIGNATURES

        Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Company has duly caused this Amendment to be signed on
its behalf by the undersigned, thereunto duly authorized.

Dated: April 28, 1999                   THE COAST DISTRIBUTION SYSTEM, INC.



                                        By:      /s/ SANDRA A. KNELL
                                            ------------------------------------
                                                     Sandra A. Knell,
                                                Executive Vice President and 
                                                  Chief Financial Officer

        Pursuant to the requirements of the Securities Exchange Act of 1934,
this Amendment on Form 10K/A has been signed below by the following persons in
the capacities and on the dates indicated.

<TABLE>
<CAPTION>

           SIGNATURE                                   TITLE                                DATE
           ---------                                   -----                                ----
<S>                                     <C>                                              <C>
    /s/  THOMAS R. MCGUIRE*             Chairman of the Board of Directors, Chief        April 28, 1999
------------------------------------    Executive Officer and Director
         Thomas R. McGuire                   


    /s/  SANDRA A. KNELL                Executive Vice President (Principal              April 28, 1999
------------------------------------    Financial and Principal Accounting Officer)
         Sandra A. Knell               


    /s/  JOHN E. TURCO*                 Director                                         April 28, 1999
------------------------------------
         John E. Turco


                                        Director                                         April __, 1999
------------------------------------
         Louis B. Sullivan


    /s/  ROBERT S. THROOP*              Director                                         April 28, 1999
------------------------------------
         Robert S. Throop


    /s/  BEN A. FRYDMAN                 Director                                         April 28, 1999
------------------------------------
         Ben A. Frydman


                                        Director                                         April __, 1999
------------------------------------
         John W. Casey


*By: /s/  SANDRA  A. KNELL                                                               April 28, 1999
     -------------------------------
          Sandra A. Knell,
          Attorney-in-Fact
</TABLE>


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